The present invention relates to devices for the handling, stocking and processing of chemical products intended for the chemical industries. In particular it concerns mixers, processing devices and routing devices capable of handling highly corrosive products, such as concentrated acids or bases. In the present application, the expression xe2x80x9celements of chemical devicesxe2x80x9d means in particular, and in a collective manner, storage chambers, tanks, heat exchangers, mixers, treatment devices and routing devices.
More specifically, the invention relates to a manufacturing process for plated products comprising at least one support part in steel and an anticorrosion metallic coating, such as elements of chemical devices or assembly parts intended for manufacturing elements of chemical devices.
The chemical industries use numerous elements of chemical devices, which are needed for handling, stocking and/or processing highly corrosive chemical products and which, consequently, have to be capable of resisting any attack from the latter.
In order to guarantee high resistance to corrosion, the elements of the chemical device usually comprise steel support parts and a metallic anticorrosion coating with a base of so-called xe2x80x9cnoblexe2x80x9d metals, such as titanium, tantalum, zirconium, a nickel-based alloy or stainless steel. The elements of the chemical device can be manufactured by mounting assembly parts, such as plates, previously coated with an anticorrosion metallic coating. The anticorrosion coating can be fixed to the support part in different ways, such as knurling, explosion cladding, hot rolling or simple covering without any junction between the plate and the anticorrosion coating.
Certain applications, such as devices with low internal pressure, need a strong link between the steel support part and the anticorrosion coating, that is to say a link with high resistance to stripping, in order to avoid separation which could, for example, lead to collapse of the anticorrosion coating. Knurling, explosion cladding and hot rolling make it possible to obtain very strong part/coating links, but these techniques can only be used when the thickness of the anticorrosion coating is less than 0.7 mm.
The applicant therefore looked for a method applicable to industrial development for fixing solidly a low thickness anticorrosion coating on a support part in steel.
The aim of the invention is a process for manufacturing a plated product comprising a support part in steel and an anticorrosion metallic coating, such as an element of a chemical device or an assembly part intended to manufacture chemical device elements, characterized in that the anticorrosion coating is fixed on the support part by brazing under controlled atmosphere, such as vacuum brazing or brazing under inert gas.
The applicant noted that the process according to the invention made it possible to fix solidly on a metallic part in steel an anticorrosion coating with a thickness less than 1 mm, or even less than 0.5 mm, possibly smaller than or equal to 0.3 mm.